Highly Selective SnCl2-Catalyzed Solketal Synthesis at Room Temperature

The selective transformation of glycerol into value-added products remains a challenging task due to its polyfunctional nature. Conversion of glycerol into 2,2-dimethyl-1,3-dioxolane-4-methanol (i.e., solketal) was efficiently catalyzed by SnCl2 at room temperature and in solvent-free conditions. Solketal is an useful additive for the formulation of gasoline, diesel, and biodiesel. Tin chloride, an inexpensive, water-tolerant, and minimally corrosive Lewis acid catalyst, has demonstrated excellent catalytic behavior in the acetalisation of glycerol with acetone to yield solketal with a higher efficiency than traditional Bronsted acids (i.e., p-toluenesulfonic acid or sulfuric acid). The effects of various parameters, such as catalyst loading, acetone/ glycerol molar ratio, and temperature on the selectivity and conversion of glycerol was investigated in detail. Although used in the homogeneous phase, the SnCl2 catalyst was easily recovered and reused without any reactivation treatment up to six times, keeping constant its activity.